This invention relates to treatments for inflammatory diseases of the skin, and more specifically to methods for devices and treating ultraviolet light-sensitive dermatoses.
Inflammatory diseases of the skin affect a large portion of the population resulting in significant morbidity. Psoriasis, for example, affects at least 1% of the population. This disease involves an abnormally fast rate of cell proliferation in the basal layer of the epidermis giving rise to red, scaly plaques and bleeding when traumatized (the "Auspitz sign"). Past methods of treatment of skin psoriasis include the application of tars, salicylic acid, steroids, ultraviolet light (phototherapy), and a combination of ultraviolet light, used in conjunction with photoactive compounds (photochemotherapy).
Photochemotherapy involves treatment with ultraviolet radiation of an affected area in combination with a topically or systemically applied medicament that sensitizes the skin to ultraviolet radiation (e.g., psoralen). Typically ultraviolet-A (UV-A) light (so-called long wave UV light) having wavelengths from 310 to 440 nm is used for this purpose. Unfortunately, successful treatment requires that UV radiation must be applied until an erythema (sunburn) is created. In some cases, the eyes of patients systemic undergoing psoralen and topical UV treatment may be sensitized to sunlight for several hours after treatment. In addition, some patients find the medicament difficult to tolerate. Furthermore, this therapy requires 20-25 radiation sessions which result in darkening of the pigmentation of the skin. In addition, treatment of scalp psoriasis in particular has been limited by two other problems. First, patients are reluctant to apply medications regularly which must remain on their scalps for hours at a time. Second, light from conventional treatment devices does not effectively penetrate hair covering the scalp.
Phototherapy involves simply UV irradiation of the affected area. For example, psoriasis has been treated with ultraviolet-B (UV-B) light having wavelengths from 290-320 nm. Other skin diseases which have been treated successfully with ultraviolet light include eczema, mycosis fungoides, and lichen planus. In addition, ultraviolet light may have a role in the treatment of seborrheic dermatitis.
Phototherapeutic methods have included the use of mercury vapor high pressure radiation devices and those UV sources having varying spectral distribution. For example, UV-B lamps such as devices which produce radiation from a metal halide or mercury vapor source and which filters the emitted UV light with colored glass have been used (see e.g., U.S. Pat. No. 4,558,700). These devices emit UV in the range of 270-365 nm (mostly 270-315 nm), and cause erythema. Devices which emit wavelengths of 320-330 nm and greater have also been used for so-called super-high-intensive phototherapy (SHIP).
There is one prior art device that is adapted to deliver UV radiation to the scalp. That device is a hair brush for purportedly promoting the healthy flow of blood to the glands and roots of hair, and for promoting vitamin D production. The hair brush has an internal UV radiation source and UV radiation-transmitting bristles of a material other than a fiber optic material (Schwedersky, U.S. Pat. No. 2,397,757). Because the bristles of this device are rigid and pointed, its use on psoriasis-affected skin heightens the incidence of the Auspitz sign, and thus is contra-indicated for treatment of psoriasis.
Therefore, a need exists for a simple device and method useful for treating affected areas of the skin, particularly those hair-covered regions such as the scalp.
Accordingly, it is an object of this invention to provide a therapeutic device for the delivery of UV irradiation directly to an area of the body afflicted with psoriasis or other related dermatoses.
It is another object of the invention to provide a therapeutic device for the efficient delivery of UV light to an affected area with reduced specular reflection at the site of delivery.
Yet another object is to provide a method of treating psoriasis and related dermatoses which is easy to administer, rapid, and which minimizes unpleasant side effects such as erythema, pigmentation darkening, and the Auspitz sign.
An additional object of the invention is to provide a method of treating psoriasis which minimizes the therapeutic sessions required to result in relatively rapid healing.
These and other objects of the invention will be apparent from the drawing description, and claims that follow.